Reproduction apparatus for printing on sheets

Abstract

A reproduction apparatus includes a print unit with print elements for ejecting an amount of ink on a plurality of sheets, of which each size in the direction perpendicular to the transport direction of the sheets under the print unit is smaller than the size of the print unit in the same direction, and a displacing mechanism for displacing the sheets in the same direction. The displacement of the displacing mechanism is so extreme that an alignment of a sheet is variable from an alignment of one side of the sheet with one end of the print unit to an alignment of the other side of the sheet with the other end of the print unit. Also a method for application by such a reproduction apparatus is disclosed.

What is claimed is: 
     
       1. A reproduction apparatus, comprising:
 a print unit comprising print elements for ejecting drops of marking material on a plurality of sheets, the print unit having two ends in a first direction perpendicular to a transport direction of the plurality of sheets; 
 a transport mechanism configured to transport the plurality of sheets towards the print unit in the transport direction; 
 a displacing mechanism configured to displace the plurality of sheets in the first direction; and 
 a controller configured to control the print unit, the transport mechanism and the displacing mechanism, 
 wherein the displacing mechanism is configured to displace the plurality of sheets in the first direction before arriving at the print unit towards such a position that at least one of the plurality of sheets aligns with one of the ends of the print unit and at least one of the plurality of sheets aligns with the other end of the print unit, and 
 wherein the displacing mechanism is configured to alternate the position of the plurality of sheets by aligning a first number of at least one sheet with the one end of the print unit and a second number of at least one subsequent sheet with the other end of the print unit. 
 
     
     
       2. The reproduction apparatus according to  claim 1 , wherein the displacing mechanism is configured to alternate the position of the sheets between a constant number of subsequent sheets. 
     
     
       3. The reproduction apparatus according to  claim 2 , wherein the displacing mechanism is configured to alternate the position of the sheets between each pair of subsequent sheets. 
     
     
       4. The reproduction apparatus according to  claim 1 , wherein the displacing mechanism is configured to align the first number of at least one sheet on which drops of marking material correspond to print data of a print job with the one end of the print unit and to align the second number of at least one sheet on which drops of marking material correspond to print data of a subsequent print job with the other end of the print unit. 
     
     
       5. The reproduction apparatus according to  claim 1 , wherein the displacing mechanism is configured to align a set of a print job to be printed on the first number of at least one sheet with the one end of the print unit and to align a subsequent set of the print job to be printed on the second number of at least one sheet with the other end of the print unit. 
     
     
       6. The reproduction apparatus according to  claim 1 , further comprising a second displacing mechanism configured to displace the displaced sheets after being printed upon by the print unit towards a single position before the sheets leave the reproduction apparatus. 
     
     
       7. The reproduction apparatus according to  claim 1 , wherein the sheets are positioned on a perpendicular bisector of the size of the print unit in the first direction before arriving at the print unit. 
     
     
       8. The reproduction apparatus according to  claim 1 , wherein at least one sheet has a size in the first direction, which is smaller than the size of the print unit in the first direction. 
     
     
       9. The reproduction apparatus according to  claim 1 , wherein a change of direction by the first displacing mechanism is controlled by the controller depending on the image data of the print jobs to be printed on the plurality of sheets. 
     
     
       10. The reproduction apparatus according to  claim 1 , wherein a change of direction of the first displacing mechanism is controlled by the controller depending on a maximum time interval that is required for a printing element to eject printing material in order to avoid clogging of the printing element. 
     
     
       11. A method for printing sheets of at least one print job on a reproduction apparatus, the reproduction apparatus comprising:
 a print unit comprising print elements for ejecting drops of marking material on a plurality of sheets, the print unit having two ends in a first direction perpendicular to a transport direction of the plurality of sheets; 
 a transport mechanism configured to transport the plurality of sheets towards the print unit in the transport direction 
 a displacing mechanism configured to displace the plurality of sheets in the first direction; and 
 a controller configured to control the print unit, the transport mechanism and the displacing mechanism, 
 the method comprising the steps of: 
 a) reading settings of the print job by the controller; 
 b) determining per the at least one print job a number of sheets (X) to be printed; 
 c) starting the transport mechanism, the displacing mechanism and the print unit; 
 and, for each print job: 
 d) determining a number of sheets (n) after which a change of displacement is to be scheduled by the control mechanism; 
 e) defining and initializing a counter (m) for counting a number of printed sheets of the print job; 
 f) checking if the counter (m) exceeds the number of sheets (X), and if so, proceeding with the next print job at step d), if any; 
 g) checking if the counter agrees with a displacement criterion for determining of the displacement of the displacing mechanism, and if so, activating the displacing mechanism to change the direction of displacement; and 
 h) printing the current sheet and incrementing the counter, and proceeding with step f).